A readily serviceable screen for excluding particulate solids from rate-controlled pressure-actuated ballcock valves of the type used in toilet tanks.
Municipal regulations regarding the use of water in the flushing of toilets generally require the use of flow-rate controls (flow controls) to limit the amount of water discharged for each flush and to discourage multiple flushes. Also, especially when the ballcock mechanism depends on a pressure differential, flow at an excessive rate can interfere with the proper functioning of the ballcock valve itself.
Accordingly, modern pressure-differential ballcock valves are mostly provided with a flow control whose function is to limit the rate of flow, making it constant over a substantial range of pressures. A pervasive problem with flow controls, and also with the pressure-responsive mechanism is its sensitivity to particulate solids that tend to plug up the necessarily small orifices. Many times this is solved in the control mechanism by placing rods in the critical orifices with clearances that movement of the rod tends to keep clear and which are too small for the particulates to pass. Also, it is common to place screens in the ballcock""s water supply riser. The problem here is evident. After a time, the upstream side of the screen becomes clogged and the valve must be serviced to flush the line and clean the screen.
This sounds like a simple matter, and to a qualified person it is. A plumber finds it a pleasant, quick and financially rewarding task, and a householder who is skilled with his hands and is knowledgeable can do the job instead. However, in conventional installations the tank must be drained, the ballcock valve removed completely, the water turned back on to flush the line, taking care to divert the stream, the screen cleaned, and the valve re-installed. The task to the average person is not simple at all.
It is an object of this invention to provide a ballcock valve with a readily removable top mechanism which can expose a readily removable and replaceable combination of screen and flow control that can be lifted out to be cleaned and to permit the line to be flushed, and then replaced along with the top. This is an elegantly simple matter which a person with almost no skill can accomplish.
This invention is carried out in a ballcock valve which has a tubular water supply riser rising into a tank. Atop the riser there is supported a pressure differential mechanism (sometimes herein called xe2x80x9cvalve workingsxe2x80x9d), whose opened or closed setting is determined by the elevation of a float in the tank.
The valve workings itself is housed in a body in a chamber formed of a base and a cap. Removal of the cap gives access to to the valve workings, and permits its removal. A combination flow-control and screen is held in the riser, directly upstream from the valve workings.
According to this invention, the screen projects into the riser to keep particulate solids in the riser, out of the chamber and out of the flow control.